Last week Clint Eastwood said that he expected Charlize Theron would join his John Edgar Hoover biopic J. Edgar alongside Leonardo DiCaprio, Armie Hammer and Judi Dench. The actress was said to be playing Helen Gandy, a Justice Department file clerk Hoover selected as his personal secretary at the age of 21, and who wound up working for him for over 54 years.

However according to a new report Theron may not be joining the film after all, and 20th Century Fox are after her for Ridley Scott’s Alien prequel.

Apparently, Theron’s reps at William Morris Endeavor were a bit ahead of the curve on their client’s willingness to star as Hoover’s longtime personal secretary Helen Gandy, putting the Oscar winner in the slightly awkward position of having to apologize to Eastwood for backing away from a role she never actually planned on accepting. All has since been smoothed over with Eastwood, but it’s also opened the door for 20th Century Fox. The studio is hoping the newly-available Theron can solve one of its more pressing problems: Casting its Alien prequel.

The site says Ridley Scott wants Noomi Rapace (Girl With the Dragon Tattoo) as his leading lady, but the studio wants an actress who is more well known. The role of Elizabeth Shaw is apparently being beefed up for Theron, who will get the new version of the Alien script sometime this week and make her decision soon.

Michael Fassbender (X-Men: First Class) and Michelle Yeoh (Memoirs of a Geish) are also thought to be up for roles as crew members, but nothing is official yet.

Update: Deadline says that Naomi Watts and Amy Adams are being looked at to replace Theron, and the actress may be about to sign on for Snow White and the Huntsman so Fox may have to make that Alien script a bit beefier.